Donovan, Katrina 

• Ph.D., Oregon State University 

• M.S., San Jose State University 

• B.S., South Dakota School of Mines & Technology

Injectable  Lipid–CMC–Bone  Ash  Hydrogel  for  Spinal  Disc  Regeneration (2 AY-SRP).

Intervertebral disc degeneration (IVDD) is the leading cause of chronic low-back pain, affecting nearly 80% of adults at some point in their lifetime and representing one of the largest contributors to global disability. Cur-rent surgical interventions (discectomy, fusion, artificial disc replacement) treat symptoms but fail to restore the native hydrated, proteoglycan-rich nucleus pulposus (NP), often accelerating adjacent segment degen-eration. The nucleus pulposus (NP) is a hydrated, proteoglycan-rich, viscoelastic tissue. Loss of hydration and proteoglycan content is a primary driver of disc degeneration. I propose that CMC hydrogels reinforced with tallow-derived lipid polymers and bone ash nano-hydroxyapatite will mimic NP hydration, mechanical response, and mineral signaling. The project will consist of i) synthesizing CMC-based injectable hydrogels incorporating lipid microspheres and bone ash, and ii) tuning crosslink density to control swelling, injectability, and compressive modulus.

The following properties will be evaluated:

1.  Rheological behavior

2.  Swelling ratio and degradation rate

3.  Compressive modulus under cyclic loading

4.  Assess in vitro NP-like cell viability and proteoglycan production.

From this project the expected outcome is an injectable hydrogels with NP-mimicking hydration, viscoelastic-ity, and bioactivity.

Regenerative Injectable Craniofacial and Soft-Tissue Filler (2 AY-SRP).

Craniofacial defects resulting from trauma, congenital anomalies, and tumor resection require materials that restore both soft tissue volume and the underlying mineralized interface. Current fillers (hyaluronic acid, sili-cone, synthetic polymers) provide cosmetic volume but lack regenerative capacity and often require repeated replacement. Simultaneously, soft tissue fillers must maintain injectability, shape retention, and biocompat-ibility—criteria that are poorly met by current mineral-reinforced systems due to brittleness and processing limitations. This project is significant because it establishes a first-in-class regenerative injectable filler com-bining mineral signaling (bone ash nano-HAp) with lipid-softened CMC hydrogels, enabling both volume restoration and regenerative tissue integration.

Soft tissue fillers must restore volume, maintain shape, and support tissue integration. Bone ash nano-hydroxyapatite provides osteogenic signaling for craniofacial regeneration. The project will consist of formu-lating injectable CMC-lipid-mineral fillers and assessing their shape retention, elastic modulus, porosity and mineral dispersion, and perform osteogenic differentiation assays and mineralization studies. The expected outcome is an injectable regenerative fillers with tunable mechanical and osteogenic properties.

Cosmetic Base Design  Rheological Optimization (2 AY-SRP).

Cosmetic moisturizers and foundations are highly relatable entry points into biomaterials research, yet most commercial products rely on petroleum-derived polymers and superficial hydration strategies that do not restore the skin’s natural lipid barrier or promote regenerative cellular responses. Emerging research high-lights the value of biomimetic lipids, hydrogel hydration networks, and mineral-rich formulations for supporting barrier recovery and long-term skin health. The lipid–CMC–bone ash biomaterial platform provides a unique opportunity to create biomimetic, regenerative cosmetic bases that combine: biomimetic lipids (barrier repair), CMC hydrogel networks (hydration & structure), bone ash nano-hydroxyapatite (mineral signaling).

This project will have two parts, a formulation component and then a performance assessment of the formu-lation. The formulation will include a prototype “moisturizer” and “foundation base” (bench-scale), 2–3 formu-lations for each prototype. The moisturizer prototype will be a lipid–CMC emulsion/gel-cream that provides hydration and a barrier feel. The cosmetic foundation base prototype: lipid–CMC dispersion with controlled yield stress (spreadability, suspension stability for pigments later). The second component is Rheology-driven performance testing that can be performed in the TECCL. The testing will include flow curves (shear-thinning for spreadability), yield stress (stays on skin; resists dripping), thixotropy/recovery (rub-in behavior), and oscillatory tests (G’/G” for “creaminess” vs “gel” feel).